mkfs/fstyp.c

   1 /*
   2  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32
  33 #include <stdio.h>
  34 #include <fcntl.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38 #include <fstyp.h>
  39
  40 /*
  41  * fstyp allows the user to determine the filesystem identifier of
  42  * mounted or unmounted filesystems using heuristics.
  43  *
  44  * The filesystem type is required by mount(2) and sometimes by mount(8)
  45  * to mount filesystems of different types.  fstyp uses exactly the same
  46  * heuristics that mount does to determine whether the supplied device
  47  * special file is of a known filesystem type.  If it is, fstyp prints
  48  * on standard output the usual filesystem identifier for that type and
  49  * exits with a zero return code.  If no filesystem is identified, fstyp
  50  * prints "Unknown" to indicate failure and exits with a non-zero status.
  51  *
  52  * WARNING: The use of heuristics implies that the result of fstyp is not
  53  * guaranteed to be accurate.
  54  */
  55
  56 int
  57 main(int argc, char *argv[])
  58 {
  59         char    *type;
  60
  61         if (argc != 2) {
  62                 fprintf(stderr, "Usage: %s <device>\n", basename(argv[0]));
  63                 exit(1);
  64         }
  65
  66         if (access(argv[1], R_OK) < 0) {
  67                 perror(argv[1]);
  68                 exit(1);
  69         }
  70
  71         if ((type = fstype(argv[1])) == NULL) {
  72                 printf("Unknown\n");
  73                 exit(1);
  74         }
  75         printf("%s\n", type);
  76         exit(0);
  77 }